A server has a mechanism for measuring power consumption or power consumption amount spent by itself. With such a measuring mechanism, power consumption (amount) may be measured for each resource such as a CPU (Central Processing Unit), a memory, a peripheral circuit, and the like. However, if multiple virtual machines (VMs) are running on a server, it is very difficult to measure power consumption of a resource for each of the virtual machines because the virtual machines share multiple resources.
There exists a technology that estimates power consumption of a virtual server by measuring CPU utilization and memory usage of an operation of the virtual server, converting them to CPU utilization and memory usage on a reference server that has a predetermined hardware configuration, and estimating power consumption on the reference server (see, for example, Patent Document 1).
There exists a technology that obtains power consumption of a virtual machine by providing a state mapping table in which power consumption of an operation corresponding to each operational state of a physical resource is specified, obtaining the number of operations actually executed by the virtual machine on the physical resource where the number is obtained by an operation counter in the physical resource, and multiplying an entry of the table by the number of operations to obtain power consumption (see, for example, Patent Document 2).